Figure captions and whitespace

[lheagy]

Many of the figures have the label caption-hack. This removes margin space, and in some places led to overlapping figure and caption. Instead, we should

• remove the caption-hack tag
• trim whitespace on figures

introduction-to-datascience-python/source/_static/style.css

Lines 7 to 9 in 313af48

	.caption-hack img {
	margin-bottom: -30px;
	}

This has been addressed in Ch 3 with #76, but will need to be addressed elsewhere.

[joelostblom]

Just a note that the caption-hack CSS class might still be needed for any images that are automatically generated by code blocks, such as our Altair charts. See the following for details as to why and the alternative approach we can use:

• Add css for figure captions and notebook with examples #5
• classification1 #3

[trevorcampbell]

I believe this is handled now